Mobile machines typically have a propulsion system for propelling them. The propulsion system of a mobile machine may include one or more traction devices (such as wheels), a prime mover (such as an engine), and components for transmitting power from the prime mover to the one or more traction devices to propel the mobile machine. In some propulsion systems the components for transmitting power from the prime mover to the one or more traction devices include one or more clutches. These clutches can be slipped to modulate the transmission of power between the components of the propulsion system for various purposes, such as for starting movement of the mobile machine and/or controlling distribution of power to the traction devices of the mobile machine as part of a traction control strategy. Unfortunately, slipping these clutches can generate significant heat, which can sometimes heat the clutches and/or other components to undesirably high temperatures.
U.S. Pat. No. 6,769,526 B2 to Iida et al. (“the '526 patent”) discloses a system for estimating the temperature of a clutch in a four-wheel-drive system. To estimate the temperature of the clutch, the system of the '526 patent estimates an amount of slippage of the clutch and an amount of torque transmitted by the clutch. Using these estimates, the system of the '526 patent estimates an amount of energy generated by the slippage of the clutch. To estimate whether the temperature of the clutch has increased, the system of the '526 patent compares the estimated value of the energy generated by the slippage of the clutch to a predetermined fixed value representative of an estimate of the amount of energy that may be typically rejected by the clutch.
Although the '526 patent discloses a system for estimating temperature increases of a clutch in a four-wheel-drive system, the system of the '526 patent may have certain shortcomings. For example, the approach of using a fixed value of assumed heat rejection rate to determine whether the clutch temperature has increased or decreased may estimate clutch temperatures with a level of accuracy that is undesirably low.
The disclosed embodiments solve one or more of the problems set forth above.